Qt Charting Component - Feedback request
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Just a quick note to report a little bit of progress. I now have this charting component working under the Qt Simulator target. Next step is to get it working on a real Symbian device. Here's a "screenshot":http://gallery.theharmers.co.uk/picture.php?/165/category/5 showing a simple example running under the simulator.
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[quote author="Michel Pacilli" date="1307918063"]hi,
really nice plots !
[/quote]Thank you.
[quote author="Michel Pacilli" date="1307918063"]
Do you use QGraphicsPathItems for the "line" plots?
And the points symbols?
[/quote]Almost. I have written my own custom QGraphicsItem subclasses. In this case the lines are drawn by a ZSplinePathItem and the points are drawn by ZPointItem. Both these classes inherit from another class of mine called ZTransformedPlotItem which allows the subclasses to easily perform transformations between the natural plot coordinate system and the usual QGraphicsView parent item coordinate system. The idea being that by replacing the coordinate system in use you can change the plot type ie switch to a polar coordinate system.
The ZSplinePathItem uses a QPainterPath internally.
[quote author="Michel Pacilli" date="1307918063"]
the look and feel seems to be really well defined, yes I'd like to play with !great project,
Michel[/quote]
Thank you again. I have a little more work left to do before I will make a first release but I am slowly getting there. Things left to do include:
- Contour plots (these are almost done)
- Bar/column charts
- More style abstractions for easier customisation
- Peformance optimisations
- Lots more testing ;-)
I'll post back here as I make progress.
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Woohoo! I've just managed to get the basic plot example (shown above running in the simulator) to run natively on Symbian^3. This feels like a major step for me and it shows that we can now relatively easily create applications containing charts on desktop, embedded and mobile targets. :D
The only changes I made compared to the same example built for desktop was to make the font size a little smaller to make better use of the available space and to call QWidget::showFullScreen() rather than QWidget::show() on the QGraphicsView. I'll try to factor the font size adjustments into the library. The choice between show() and showFullScreen() is down to the application writer.
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"This question":http://developer.qt.nokia.com/forums/viewthread/6950/ was split off as a separate topic.
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Hey Sean,
Impressive work!
Charttypes that I miss in your list are the financial stock charts like bar charts (open, high, low, close) and candlestick charts. I know that many developers are looking for something like that. I am using qwt for that purpose but it does not support these types either.
It would be great to have these as well.
Kind regards,
Eric -
Ok good. Can't wait for your first release.
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Sean,
Bump.
How can I use your widget from within QML?
Can I draw xy science plots using data from a C++ class (say a std::vector) ?
In my app, the data may arrive any time, so how can I notify the plot widget to draw the new data?
Is there an example ?Thank you for the great work. It seems what a lot of people have been waiting for!
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Hey Guys,
sorry for the delays on this. I'm in the middle of changing jobs and things are very hectic still at my existing job. I hope to get version 1.0 out very soon now.
Victor: I am playing around with an idea on how to integrate this into QML 1. As for QML 2 I am not sure what is the best route to go down as yet so that requires some more experimentation.
